Heretofore in the use of microscope slides, after the slide has been completed with the specimen thereon and stained, it is necessary to apply a thin, transparent, protective cover thereon. In the past this has been done by first applying a small amount of cement or glue to the microscope slide and thereafter manually applying a glass or thin plastic cover over the microscope slide for registry therewith. One of the difficulties has been the correct juxtaposition manually of the cover onto the microscope slide. Another problem has resided in the entrapment of air bubbles between the cover and slide during the manual assembly operation.